I have created RPM for centos-5 with patches you proposed in pop-before-smtp-conf.pl. For me it was required to patch pop-before-smtp to make it use perl Date::Format and Date::Parse installed with zimbra-core, instead of installing it from CPAN.
These changes for /opt/zimbra/conf/log4j.properties.in and /opt/zimbra/conf/postfix_recipient_restrictions.cf are done by post install script of the RPM and they are reverted at uninstall of the rpm by preun script.
If anybody interested I can place this rpm, spec and patch somewhere for viewing/downloading.

How did you managed zimbra to write Pop3 authentication messages to /var/log/maillog?
Or have you changed it to be /opt/zimbra/log/mailbox.log and did not mentioned it here in your previous posts?
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Sergey.

Support for IMAP

Due to out zimbra implementation being a migration from an existing server with hundreds of users all using pop-before-smtp, we were require to enable this tool as well. Everything from the mnxsolutions blog posting above worked fine except that the INFO multiline authentication patterns did not catch IMAP logins, so we changed them to the following and everything appears to be working correctly, both POP3 and IMAP: